APS March Meeting 2010
Volume 55, Number 2
Monday–Friday, March 15–19, 2010;
Portland, Oregon
Session W19: Focus Session: Synchrotron X-ray and Neutron Techniques in Soft Matter and Biological
11:15 AM–2:15 PM,
Thursday, March 18, 2010
Room: B118-B119
Sponsoring
Units:
DPOLY DBP
Chair: Zhang Jiang, Argonne National Laboratory
Abstract ID: BAPS.2010.MAR.W19.1
Abstract: W19.00001 : Characterizing 3-D Assembly of Block Copolymer Films using Rotational Small Angle Neutron Scattering
11:15 AM–11:51 AM
Preview Abstract
Abstract
Author:
Ronald Jones
(NIST)
Directed Self-Assembly (DSA) using graphoepitaxy, chemically patterned
templates, and directed fields has been shown to be an effective route to
achieving long range order over short time scales in block copolymer films
designed for use as sacrificial resists. However, key questions remain
regarding the materials-processing relationship that drives assembly in thin
films. Understanding these relationships will become increasingly more
important in emerging applications such as in photovoltaics and
nanostructured membranes where the polymers are functional components.
Utilizing a methodology to sample the entire 3-dimensional fourier space of
a thin film coating, termed Rotational Small Angle Neutron Scattering
(R-SANS), our group has discovered a complex process window that drives
orientation and order in thin film block copolymer assembly. Data from
R-SANS is complemented by specular neutron reflectivity (NR) and real time
measurements using grazing incidence small angle x-ray scattering (GI-SAXS).
In this talk, I will highlight some of our recent results that elucidate the
effects of solvent content, evaporation rate, and thermal history on the
average orientation and orientation distribution in block copolymer films.
Of particular interest is the previously unreported effect of thermal
gradients. Using static thermal gradients, we show that the kinetics of
assembly are dramatically faster. Specifically, grain sizes on the order of
10s of microns are achievable in minutes for a system that would require
$>$10 h to achieve the same results in a thermally uniform environment. The
scaling of kinetics as a function of the static thermal gradient is also
discussed and models of the physical processes involved presented. The
complex evolution of morphological orientation is then further biased
through the application of dynamic gradients in a technique we label as cold
zone annealing, a technique suitable for manufacturing methods such as
roll-to-roll processing.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.W19.1